I'm running wvo in a 84 300d. I need to hook up low pressure fuel pump in my trunk ro help push the oil to the engine.

I want to know is there any trunk wire I can splice into that will supply me with 12v only when the engine is running?

Thanks.

Pete

Power antena. Better yet, just run a new dedicated circuit for your pump.

__________________
Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

To have power anywhere in the car with the engine actually running (as opposed to "switch in position #2 RUN") would take a dedicated relay working off of the alternator light. That way, once the engine is actually running and the alternator producing current, the alternator light goes out, the relay trips off, and your accessory pump gets power.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I really just need power only when the key is in the run position but thanks for reply.

I just ran a wire from the engine compartment back to the trunk.
I actually went through a little hole near the emergency kit on the back deck.

Thanks.

pete

This method may save some wiring and some work.

1) Tap the antenna cable to get a 'switched' 12V. I think there is a wire in the cable bunch which is switched whether the radio is on or not. Run it thru a 20A relay to switch ...
2) Tap the trunk light for 'constant' 12V and wire it thru the relay.

Bingo. Now you have a switch 12V with a build-in fuse. It should have enough juice to drive the grease pump. This is an alternative anyway.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.